<!DOCTYPE html>
<html>

<head>
    <meta http-equiv="Content-type" content="text/html; charset=utf-8" />
    <title></title>
    <link rel="stylesheet" href="visible.css" type="text/css">
    <script src="../scripts/lib/jQuery/jquery-3.4.1.js"></script>
</head>

<body>
    <h2>可见性筛选选择器</h2>
    <h3>:visible/:hidden</h3>
    <div class="left">
        <div class="div">
            <a>display</a>
            <p id="div1" style="display:none;">display</p>
        </div>
        <div class="div">
            <a>width</a>
            <a>height</a>
            <p id="div2" style="width:0;height:0">width/height</p>
        </div>
        <div class="div">
            <a>visibility</a>
            <a>opacity</a>
            <p id="div3" style="visibility:hidden;opacity:0">visibility</p>
        </div>
    </div>

    <p id="show"></p>
	<script type="text/javascript">
		function show (ele) {
			if (ele instanceof jQuery) {
				$("#show").html($("#show").html()+'<br/>元素的长度的 = ' + ele.length)
			} else {
				alert(ele+' 不是jQuery对象')
			}
		}
	</script>


    <script type="text/javascript">
    	//查找id = div1的DOM元素,是否可见
    	show($("#div1:visible"));
    </script>

    <script type="text/javascript">
    	//查找id = div2的DOM元素,是否可见
    	show($("#div2:visible"));
    </script>

    <script type="text/javascript">
    	//查找id = div3的DOM元素,是否可见
    	show($("#div3:visible"));
    </script>

    <script type="text/javascript">
    	//查找id = div1的DOM元素,是否隐藏
    	show($("#div1:hidden"));
    </script>

    <script type="text/javascript">
    	//查找id = div2的DOM元素,是否隐藏
    	show($("#div2:hidden"));
    </script>

    <script type="text/javascript">
    	//查找id = div3的DOM元素,是否隐藏
    	show($("#div3:hidden"));
    </script>



</body>

</html>